Process and apparatus for separating palpable powder by sustentation



June 23, 1925.

E. A. LEVY ET AL PROCESS AND APPARATUS FOR SEPARATING PALPABLE POWDER BY SUSTENTATION Filed Feb. 26. 1923 4 m In 1 I I vwvrfif 4 J U. Z I m s i v 4.- a m 6 x a 2 1 m 0, a a- Patented June 23, 19 25 i'ifiiian ill as a ILEVY AND Josssxstm rmmea, Meme-o:

raocnss AND APPARATUS FOR SEPARATIN'G rnnrnnnnrownnn Bi sUs'rnn'rA'rioN.

Application filed Feeruary 26, 1923. Serial No. 621,362.

To all whom it may concern:

Be it known that we, EPHRAIM ANDRE LivY, a citizen of the French Republic, residing at Mexico city, Federal District,

Mexico, and J osn SAFONT, a citizen of the United Mexican States, residing at Mexico city, Federal District, Mexico, have invented certain new and useful Improvements in Processes and Apparatus for Separating Palpable Powder by Sustentation, of which the following is a specification,

This invention relates to a process and machine for pulverizing solids and continuously separating the impalpable particles by suspension of all such particles ground from said solids to the fineness required for its temporary suspension in a current of air rising through obstructed funnels, thereby leaving behind in the mill the largest particles and such others which, being unable to maintain themselves suspended long enough to raise up through the entire length of the obstructed funnels, falls back to the mill where the heavier particles drop through a grate to the starting point.

These heavier particles are then raised by a conveyor and again charged from above to the mill for further treatment. The ob ject of our invention is to avoid sifting, decantation, filtration and similar treatment generally used, and yet obtaining by suspension of the'milled product in a weak current a powder of an impalpable character as the only grading.

So far, it has been found that pulverizers by grinding stop after working for a short time because the mill itself expels along with the particles more air than enters, and thereby sufiocates itself by forming a vacuum in the mill. In our apparatus an open circuit is established by a respirating and loading port covered by a curtain.

Referring now to the drawing,

Fig. 1 is an elevation of the plant;

Fig. 2 is a top View of said plant;

Fig. 3 is a side view of the plant, one of the settling rooms being omitted; and

Fig. 4 shows a side view partly in section and an end View partly broken away of the grate.

On the floor (1) is a support (2) with a well lmown grinding mill (3) provided with hammers. The interior of the mill is connected along the horizontal diametrical line with opposite funnels (4) leading to the settling rooms (5), each having a window (6) and a door (7).

The interior of said funnels carry inclined lower obstructing deflectors (8) forming passages at (9) and (10) for the powder. Further within the funnels (4) are other deflecting plates (11) and (12) attached by their upper edges to the inner wall of the funnels.

An elevator (13) provided with buckets is connected at the top by pipe (14) to the mill, and at the bottom by the inclined discharge (15) in the support (2) to the usual iuiived grate (16) at the bottom of the mill This grate indicated at 16 is just below the hammers of a known type of grinding mill and the bars of said grate are disposed on a curvature to correspond with the interior of the mill.

A blower (17) leads air to the pipe (14) for increasing the ascending current in the funnels (4). The blower (17) is supported on the standard (18) and receives rotation by transmission (19) from pulley (20) and motor (21). The elevator is also connected to said pulley by belt (22) and to the mill by the belt (23).

The shaft (24) of the elevator is open at (25) near the floor (1) and is provided with a curtain (26).- The plant is at (25) charged with solids and by (24) and (14) these solids are brought to the mill (3), where the finest particles are blown up through the funnels (4), and if sufiiciently light shall continue to the settling rooms (5). The heavier particles fall back into the mill, pass through the grate (16) and commence another trip up the shaft (24) back to the mill (3), in such time that the mill has no time to become clogged or suffocated.

How often any particle goes through the cycle depends on its gravity. As soon as it passes over to the settling rooms, and but I one grade of powder is obtained, namely has attained suspension capacity, then it pair of transverse funnels having deflectors said grate hack into the mill for regrinding'. therein; a pair of settling chambers each in In testimony whereof We have hereunto communication with one of. said funnels; gneql Our names at Mexico City, Federal 10 means for blowing a current of air into the l C this 1 h day of February,

5 mill and through said funnels; and an ele- 1923- vator for feeding material to said mill and EPHRAIM ANDRE LEVY. I to reconvey the material which falls through J OSE SAFONT. 

